This invention relates to a dynamic mixer which comprises a housing including a substantially cylindrical chamber portion defining a longitudinal axis and having at its rear end inlet means adapted for connection to supply means containing the components to be mixed, and at its front end a discharge opening for the mixture, and a mixer element disposed within the chamber portion for rotation about the longitudinal axis.
A mixer of this type is known from DE-U-8,717,424. In the known device, the chamber portion of the housing enclosing the rotary mixer element has its rear end sealed by a cap provided with openings through which hoses may be inserted. The components to be mixed are supplied via the hoses from supply cartridges, out of which the substances may be discharged by pistons. The use of hoses is possible with substances of limited viscosity only.
In a further mixer known from EP-A-0 087 029, a massive connecting piece is provided with supply bores for connection to cartridges. While this construction is suitable for materials of high viscosity also, substantial friction will occur in the supply bores of the connecting piece, so that a propelling device of correspondingly sturdy design is required for discharging the components from the cartridges.
In a further dynamic mixer known from DE-A-3,635,635, the housing is rearwardly open and fastened via a bayonet-type connector to a holder which is provided with separate supply channels for the components. In this device, there is a danger of contamination by, and cross-contamination between, the components when the mixer is exchanged, particularly in case of stringy substances. This may result in material hardening in a part of the device which is not replaced together with the mixer.